Click on map to open large map in new window (Map updated: 11 August 2009)

Click here to view an interactive map of the Northern Ireland dataset as currently collated by CEDaR.The map is generated through the NBN Gateway using their Interactive Mapping Tool.

While natural limestone will attract this species it is often more plentiful on artificial substrata such as boundary wall tops, concrete posts and mortar where there is less competition from lime-loving lichens. The crusts may begin as grey-green speckled or granular stains which later become thicker and cracked. The 1mm-diam. discs which form as soon as the thallus has established resemble black fruit gums in miniature and occur either singly or in clusters. A useful microscope character (look at a squashed slice of the disc) is the lack of any strong pigmentation around the base of the disc (fruit). This helps to eliminate lookalike species such as Clauzadea monticola.